Part 8

It is still by no means easy to decide upon the changes of color which occur in the blood during respiration; for this should appear connected, not merely with the presence of certain gases in the blood, but upon a true change in the composition of hematosine, which analysis cannot direct.

Stevens first attracted the attention upon the influence which saline bodies have upon the color of the blood. If dark, venous blood is put in contact with a solution of common salt, glauber salt, nitre, or carbonate of soda, it becomes as vermilion colored as if it had been truly arterialized; on the contrary, the presence of carbonic acid impedes this action, and gives to blood, so reddened by a salt, not in excess, the dark tint of venous blood.

If we consider, therefore, the arterial tint to be due to the material combination of the coloring matter with the saline constituents of the serum, this will be darkened, when, by passing through the capillary system, the blood takes up an excess of carbonic acid; and again, in the lungs, when the carbonic acid is replaced by oxygen, the vermilion color is restored, not by any active agency of the oxygen, but by the natural tint of saline hematosine becoming evident.

Although this theory of the change of color is by no means free from objection, it still appears to be better founded than any other that has been proposed.

_Animal Heat._—The phenomena of respiration consisting mainly in the conversion of carbon into carbonic acid by union with oxygen, the heat which is developed in the body of all red blooded animals has been naturally referred to that source; and as we know that the change from the arterial to the venous condition of the blood occurs at every point of the system, the almost complete equality of temperature throughout the body in health is explained. That the great source of heat is the respiratory process, is abundantly proved by the temperature being highest in those animals, and in the same animal, at those periods when the circulation is most rapid and the quantity of air consumed the greatest. But it has been calculated that the heat evolved by the combustion of the quantity of carbon thrown off from the body in twenty-four hours is no more than eight-tenths of the quantity generated in the body during that time, and the origin of the remainder must be found in the action of the muscles and the nervous power, which appears of itself to be a distinct source of animal heat.

ANIMAL CHEMISTRY.

SECTION TWO.

_Composition of the Digestive Organs and of their Secretions—Chemical Phenomena of Digestion_.

_Mucus._—The living membrane of the alimentary canal is moistened with a liquid possessing many of the characteristics of vegetable mucus, but containing nitrogen. It is a thick, tenacious substance, which contains, dissolved in the water through which it is diffused, the ordinary salts of the serum of the blood; it swells up with water to a considerable mass, but without dissolving; it dissolves in alkaline liquors, and is precipitated therefrom on the addition of an acid and the tincture of galls; the mucus from different parts of the mucus membrane is, however, by no means identical in properties.

The liquid secreted by the internal surface of the stomach—the gastric juice—which exercises an important influence on digestion, differs essentially in its character from mucus. When the stomach is empty and contracted, it contains ordinary mucus; but if even indigestible substances are introduced, and still more, after taking proper food, a liquid is abundantly poured out, which is colorless or pale yellow, and contains a very small quantity of solid matter (two per cent.), which consists principally of inorganic salts (common salts and sal ammoniac, with a trace of a salt of iron); it is specially characterized by the presence of a notable quantity of free muriatic acid, the proportions of which vary with the activity of the digestive powers at the time. This gastric juice possesses the remarkable property of softening down and dissolving fibrine and albumen, and thus converts the masses of food into the uniform pulp (chyme), from which the absorbing vessels of the small intestines take up the nutritious elements.

If we form an artificial gastric juice by mixing together the muriatic acid and salts in the right proportions, it is found to be totally incapable of dissolving the materials of the food, and, indeed to be quite inactive towards digestion. The organic material of the gastric juice, although its quantity be so minute, is, therefore, essential to its powers, and these may be perfectly conferred upon the previously inactive, artificial juice, by the addition of a little of the mucus of the stomach or by steeping in the acid liquor, for a short time, a small portion of a mucous membrane, and filtering the liquor; for this purpose it is not even necessary to use the mucous membrane of the stomach, for that of the bladder has been found to answer equally well. The substance which is dissolved out of the membrane in these cases has been termed pepsine. It has not been obtained in a truly isolated or pure form, but its properties are very remarkable. For its full activity it requires the presence of a free acid, as the artificial gastric juice becomes much less active in dissolving food when neutralized by an alkali, though it retains other properties, as that of coagulating milk-like rennet. If the artificial juice be precipitated by nitrate of lead, the precipitate washed, and then decomposed by sulphuret of hydrogen; the solution thus obtained possesses all the digestive powers of the juice. Hence, the pepsine and muriatic acid act together, by combining with oxide of lead.

Pepsine appears to be completely decomposed by contact with alcohol or boiling water; its powers are also destroyed by deodorizing substances; the solution of albumen and fibrine in gastric juice differs essentially from their solution in muriatic acid, as in the former case the quantity of acid is very minute, in relation to the quantity of material dissolved, and after solution the acid remains quite uncombined.

The action of the stomach in digestion, appears, therefore, so far as our actual knowledge extends, a purely catalytic fermentative action; one in which the active excitant is an organic substance (pepsine), secreted by the mucous surface, and whose properties are developed by the presence of muriatic acid, which is secreted at the same time. The new products into which the food, fibrine, albumen, gluten, starch, oils, sugar, etc., are converted, and which collectively constitute the white uniform pulp, termed by physiologists chyme, have not been made the subject of accurate chemical researches.

In the mouth the mass of nutritive material is acted on by a liquid which is secreted by the salivary glands, the saliva. It is alkaline, and holds in solution not one per cent. of solid matter, which contains some carbonate of soda and common salt, admixed mucous, and a peculiar organic body, termed salivary matter.

This last substance is soluble in water; its solution is not coagulated by heat, nor precipitated by tincture of galls, corrosive sublimate, acetate of lead, nor by acids. The pancreas, so similar in structure to the salivary glands, has a different secretion; it contains no salivary matter, but albumen and some salts; it is generally slightly acid.

_Composition of the Bile._—The precise part which this remarkable secretion performs in the animal economy is not yet fully known; it has been the subject of repeated and accurate chemical examination, although, from the facility with which its elements are transferred into other bodies, by the action of the reagents employed, every succeeding analysis has led to different results.

_The Coloring matter of the Bile._—is present during health but in small quantity, but in disease it sometimes accumulates so as to form solid masses. When pure, it is a reddish-yellow powder, which is scarcely soluble in water or in alcohol, but dissolves easily in a solution of caustic potash. This solution is of a clear yellow color, but when exposed to the air it becomes deep green, absorbing oxygen. This change is remarkably produced by nitric acid, and it is indeed the reaction by which the presence of the bile in the serum of the blood, in the skin, in the urine, and eyes, etc., may be shown in cases of jaundice.

_Chyle and Lymph._—The nutritive materials extracted from the food by the absorbing vessels of the intestines, is thrown into the thoracic duct, where it meets with another fluid, which is transmitted to the same vessel from all parts of the body by the colorless veins or lymphatics. The fluid from the intestines is termed chyle; that from the body is generally termed lymph. It is the mixture of these that has alone been examined, for the vessels which carry either separately are too minute to allow of the extraction of their contents in a pure form.

When taken from the thoracic duct, a few hours after a meal, when, probably, the chylous element prevails, it is whitish, opaque, liquid, like milk, with generally a reddish shade; a short time after separation from the body, it coagulates; the clot is at first pale, but it soon becomes light crimson red; the milkiness of the serum is due to the presence of oil; it contains albumen, and coagulates by heat; except that it is more dilute, and that the hematosine is for the most part absent, the chyle and lymph have the same composition as the blood. It appears to vary, however, with the nature of the food, as Dr. Prout found the chyle of persons fed on vegetables to contain a much smaller quantity of albumen than when they had had animal food.

Dr. Prout also indicates in chyle the presence of a substance which he terms incipient albumen, which is not coagulated by heat, except after the addition of acetic acid; the properties of this form of albumen, however, are not fully known.

_Constitution of the Urine in Health and Disease._—The nature of this secretion has at all times been an object of considerable interest to the chemist, from the indications which changes in its composition give of diseases of important organs and from the number and interest of the different organic substances it contains. As in almost all other branches of animal chemistry, Burzelius first determined its composition, and lately Lecaner has ascertained with great care the limits to which the proportions of its ingredients may vary in health, and this established a correct basis of comparison for urine in the various conditions of diseases.

_Of the Urine in Disease and after Death—Urinary Calculi._—To the chemist, the indications of disease of the urinary and digestive organs, formed by changes in the composition of urine, are most valuable. The majority of the substances which are taken into the circulation, but are incapable of assimilation to our organs, are thrown off by this secretion, and hence a variety of medicinal substances may be traced to it after having been ingested, sometimes quite unaltered, at others modified in their natures. Thus if alkaline salts of organic acids be taken into the stomach, the organic material is oxidized, probably during the action of respiration, while the alkali passes into the urine in the state of carbonate. If, however, the organic acid be taken uncombined, it escapes decomposition, and, passing into the urine, produces an abundant precipitate of salts of lime. In the case of the tartaric acid and oxalic acids, some organic bodies, as aspharagine and the oil of turpentine, are decomposed, and the products which they form are execreted, giving to the urine peculiar odors; in the latter case like that of violets.

The majority of coloring matters are thrown out of the system by this secretion, while others are not so given off.

The mineral acids—alcohol, camphor and most metallic salts—do not pass into the urine to any sensible degree.

_Urine in Diabetes._—The most remarkable change in the nature of urine occurs in Diabetes Mellitus, it is voided in great quantity; it is found to contain a great quantity of grape, sugar, and very little urea.

It was supposed that in this disease urea ceased to be formed by the system, and was replaced by sugar; but it has been shown that, although the quantity of urea is very small in any one specimen of urine, yet the total quantity is so much increased that in twenty-four hours the natural quantity of urea is secreted; the secretion of sugar being an act of faulty digestion, and totally unconnected with the urea. These results have been fully confirmed by experience.

The diabetic urine sometimes contains albumen, which arises from complications of other forms of disease.

All that has been said in the former chapter about the solid and fluid constituents of the human body may, at first sight, and to a great many, seem to be superfluous and out of place in a work of this kind. It is true that the different modes of preserving bodies, as explained in this book, do not require this long dissertation on animal chemistry in order to be understood; still, when we consider that the chemicals used in these different processes have an object to accomplish, it must be granted that a thorough knowledge of the constituents of the body, their composition and chemical proportion, will, to a great extent, explain the reason why these same chemicals are used in preference to others.

The secondary object, which is not less important, consists in the fact that a thorough knowledge of the animal chemistry of the human organism is most necessary to understand the different changes which take place in the formation of the different juices and tissues of the body, when they enter into combination with the chemicals, the object of which is to render them imputrescible.

However, the study of these combinations affords a simple and clear explanation of the means resorted to in order to preserve bodies.

GANNAL’S PROCESS OF EMBALMING.

WITH MODIFICATIONS.

This process, which has been successfully employed in Europe for a long time, for the purpose of embalming bodies and for the preservation of anatomical preparations, is still practised extensively, owing to the cheapness of the materials used and to the simplicity of the modus operandi.

The embalming fluid in this instance is composed as follows, viz.:

Sulphate of alumina, 4 pounds. Arsenious acid, 4 ounces. Creasote, 4 ounces. Water, 1 gallon.

To prepare this fluid, an explanation of its constituents is required.

There are two different kinds of arsenious acid, the opaque and the transparent. This latter variety (the transparent) should be selected in preference to the other, on account of its greater solubility; the acid must also be procured in crystals, and not in powder, as it will, in the first place, dissolve quicker, and will not be liable to be adulterated. The water must then be heated to 55°, and the acid dissolved in it. The sulphate of alumina is then to be added, and, after being completely dissolved, let the solution cool off to the usual temperature; then add the creasote, and, after stirring gently, the solution is ready for use.

Lay the body on an inclined board, as described in a former chapter, and, after thoroughly cleansing with water and soap, saturate well with a concentrated solution of alum; the body should be kept well moistened with the solution, as prescribed in the processes of embalming already given, until the operation is completed.

Through an opening made in the skin of the abdomen, and immediately over the transverse part of the colon, the bowels and the stomach will then be revealed, which must be emptied of their contents and properly cleaned, and injected with the above preparation.

After the contents of the abdomen have thus been treated, the whole abdominal viscera is to be heavily sprinkled over with tannic acid, until the acid forms a layer about one-half inch in thickness between the bowels and the skin of the abdomen; the flaps of the skin are then brought together and neatly sewed up.

The femoral vein is then opened. The femoral vein ascends the thigh in the sheath of the femoral artery, and, entering the pelvis beneath Poupart’s ligament, becomes the external iliac vein. In the lower part of its course, it is situated on the outer side of the artery; it then becomes placed behind that vessel, and at Poupart’s ligament lies to the inner side. It receives the muscular veins and propenda, and, through the saphenous opening, the internal saphenous vein.

The blood, in some cases, will issue very freely, and the flow of it must continue until the embalming fluid makes its appearance.

To inject the circulatory system, extend the left arm at a right angle with the body, and open the axilliary artery about three inches from the arm-pit. The axilliary artery is a continuation of the sub-clavian artery; it passes through the axilla or arm-pit into the arm, and is called the axilliary artery; that part of its continuation into the upper arm is called the brachial artery, and in the fore arm it divides into the radial and ulnar arteries, which are distributed to the hand and fingers.

Through the opening thus made in the axilliary artery two gallons of embalming fluid may be injected, or such quantity as may be found necessary to completely fill the arterial and venous systems.

After the blood has ceased to flow from the opening in the femoral vein, the wounds must be sewed up, and the body, anointed with the solution, left to dry in a cool, well ventilated place.

The surface of the body and also the face may be mottled in some places with white spots, but the skin will soon assume a uniform color, and the blotches will disappear.

After the solution on the body has become sufficiently dry and has penetrated the pores of the skin, the excess of moisture must be wiped off with a clean towel.

The nostrils should be hermetically sealed, by introducing into them some cotton, well saturated with gum shellac dissolved in alcohol.

The eyes must be well closed, and, if no other means at hand, the lids must be sewn together with a small circular needle, and some silk, saturated in spirits of turpentine.

The body is then saturated with a thin coating of turpentine; and after the turpentine is dry, the clothing can be put on, and the body is then ready for interment.

As shown by the preceding, this process is very simple, and has given satisfactory results in all cases, although the amount of embalming liquid and the composition thereof vary in all cases, and according to the temperature of the season and country.

For instance, if the body to be embalmed is that of a very fleshy person, and it be in the summer season, when animal substances are more prone to putrefy than at other seasons, the embalming fluid must be altered as follows, in its quantitative composition:

Sulphate of alumina, 6 pounds. Arsenious acid, transparent, 4 ounces. Creasote, 6 ounces. Water, 1 gallon.

For the minor parts of this process, as, for instance, the closing of the eyes, mouth, etc., the reader is referred to previous processes already given in former chapters.

The most reliable composition yet found for embalming purposes, and the one which has given the most satisfactory results, is the following:

Alcohol, one gallon; dissolve into it eight ounces of corrosive sublimate, and, after complete solution, add two pounds of creasote. This solution, for injecting purposes, has never failed to accomplish the purpose, and has given the most astonishing results. The only objection to its use, but one which does not in reality carry any weight with it, is the fact that the solution will produce a white scar on the skin of the body wherever it may be dropped; but a very moderate amount of care in the use of it will preclude the possibility of such an accident.

The embalming of bodies by injection has so far occupied our attention. We will hereafter pass briefly in review the process of maceration employed in the preservation of bodies.

EMBALMING BY MACERATION.

The process of embalming bodies, as at first practised, was founded on the principle of complete immersion of the body into some bath composed of antiseptics, which, by being absorbed by the system, rendered the tissues imputrescible, much in the same way as we now preserve anatomical preparations by immersing in alcohol.

At the commencement of this century a process of embalming was brought out in Europe, and succeeded very well for some time; but after a certain period, Mr. Gannal and others inaugurated a new system of preserving the dead, and the process of maceration was abandoned, and has not since been revived to any extent. The following is the manner of treatment to which a body was subjected in the above process:

The body was washed thoroughly with soap and water; then the abdomen was opened and the sternum raised; the thoracic as well as the abdominal viscera was then removed altogether, as also the brain.

The body was then immersed for one week in a strong solution of alum and nitrate of potash; the body was then taken out and the cavities filled with tow and powdered arsenic; the bowels, lungs, liver, etc., in fact all the viscera, were buried separately.

The body was then completely buried in dry sand for the space of ten days, to absorb all the moisture contained in the tissues, and was then dressed in the funeral habiliments and placed in a leaden coffin, hermetically sealed; a small, thick glass, immediately over the face, allowed the friends to obtain a view of the features.

This process has been found objectionable for a good many reasons; in the first place, the eviscerating of the body is a repulsive feature of it, and not to be had recourse to when less barbarous means are at hand; secondly, the skin of the body assumes a yellow and wrinkled appearance, which, if it does not entirely destroy the cast of the features, alters the general appearance so much as to render them very different from the natural appearance.

At any rate, the method of preserving bodies by the above means has entirely fallen into disuse, and as, with our perfected improvements in this branch of the undertaking business, we are able to do away with the most repugnant features of it, this system has been superseded by the less objectionable and more effective arterial injections.

LAWS OF HEALTH.

Undertakers, like physicians and all those who may be called at any time of the day or night to make use of their physical and mental faculties, whose duties compel them to breathe the foul effluvia of the sick chamber, or the noxious gases generated by the dead, even to come into direct contact with every variety of contagious or epidemic disease—such professionals find it to their interest and physical welfare to observe certain rules of living in accordance with the requirements of their calling.

It is a matter of great importance that their diet, clothing and habits be regulated by certain laws, which will, to a great extent, reduce the dangers to which they are exposed in the discharge of their duties.

DIET.